Abstract
This is the first attempt to evaluate the impact of four salinity levels on the color parameters, pigments, polyphenols, flavonoids, and antioxidant capacities of four promising A. lividus genotypes. The color parameters, such as the yellowness/blueness (b*) and the chroma (C*); the antioxidant components, such as the polyphenols and flavonoids; and the antioxidant capacities of the leaves were remarkably increased by 39, 1, 5, 10 and 43%, respectively, at 50 mM of NaCl, and by 55, 5, 60, 34, 58 and 82%, respectively, at 100 mM NaCl concentrations. The green tower and SA6 genotypes were identified as tolerant varieties. The total phenolic content (TPC) and the total flavonoid content (TFC) played vital roles in scavenging reactive oxygen species (ROS), and they would be beneficial for the human diet and would serve as good antioxidants for the prevention of aging, and they are also essential to human health. A correlation study revealed the strong antioxidant capacities of the pigments and antioxidant components that were studied. It was revealed that A. lividus could tolerate a certain level of salinity stress without compromising the antioxidant quality of the final product. Taken together, our results suggest that A. lividus could be a promising alternative crop for farmers, especially in saline-prone areas in the tropical and subtropical regions.
Highlights
Vegetable amaranth (A. lividus) is a C4 dicotyledonous plant that belongs to the family, Amaranthaceae
In the case of the a* value, the highest value was found in the SA3 (9.44), followed by the SA6 (8.17), and the red tower (−12.95), and the lowest value was observed in the green tower (−23.55)
Under medium salinity stress (MSS) and SSS conditions, the leaf color parameters, such as the b*, the c*, the total polyphenol and flavonoid contents, and the total antioxidant activity of A. lividus leaves were very high in comparison to the control conditions, which allows for the assignment of A. lividus as a valuable food source for human diets and health benefits
Summary
Vegetable amaranth (A. lividus) is a C4 dicotyledonous plant that belongs to the family, Amaranthaceae. Bioactive compounds play an essential role in protecting against cancer, atherosclerosis, arthritis, cataracts, emphysema, retinopathy, and neurodegenerative and cardiovascular diseases [11–13]. Because it is a major abiotic stress, salinity has serious adverse effects at different stages of plant development and growth [14]. Salinity stress leads to severe changes in photosynthesis and photorespiration activities [16]. At the initial stage of salinity stress, osmotic stress and ion toxicity occur, which may cause water loss, the interruption of the membrane, nutritional imbalance, changes in the enzyme and antioxidant activities, and an increase in the reactive oxygen species (ROS) [17]. An excessive accumulation of ROS (singlet oxygen, superoxide radical, hydroxyl radical, and hydrogen peroxide) can lead to oxidative damage in the plant [18]. Betaxanthin and betacyanin have shown antioxidant activities under stress conditions [20]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call